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Pontisso I, Ornelas-Guevara R, Chevet E, Combettes L, Dupont G. Gradual ER calcium depletion induces a progressive and reversible UPR signaling. PNAS NEXUS 2024; 3:pgae229. [PMID: 38933930 PMCID: PMC11200134 DOI: 10.1093/pnasnexus/pgae229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 05/29/2024] [Indexed: 06/28/2024]
Abstract
The unfolded protein response (UPR) is a widespread signal transduction pathway triggered by endoplasmic reticulum (ER) stress. Because calcium (Ca2+) is a key factor in the maintenance of ER homeostasis, massive Ca2+ depletion of the ER is a potent inducer of ER stress. Although moderate changes in ER Ca2+ drive the ubiquitous Ca2+ signaling pathways, a possible incremental relationship between UPR activation and Ca2+ changes has yet to be described. Here, we determine the sensitivity and time-dependency of activation of the three ER stress sensors, inositol-requiring protein 1 alpha (IRE1α), protein kinase R-like ER kinase (PERK), and activating transcription factor 6 alpha (ATF6α) in response to controlled changes in the concentration of ER Ca2+ in human cultured cells. Combining Ca2+ imaging, fluorescence recovery after photobleaching experiments, biochemical analyses, and mathematical modeling, we uncover a nonlinear rate of activation of the IRE1α branch of UPR, as compared to the PERK and ATF6α branches that become activated gradually with time and are sensitive to more important ER Ca2+ depletions. However, the three arms are all activated within a 1 h timescale. The model predicted the deactivation of PERK and IRE1α upon refilling the ER with Ca2+. Accordingly, we showed that ER Ca2+ replenishment leads to the complete reversion of IRE1α and PERK phosphorylation in less than 15 min, thus revealing the highly plastic character of the activation of the upstream UPR sensors. In conclusion, our results reveal a dynamic and dose-sensitive Ca2+-dependent activation/deactivation cycle of UPR induction, which could tightly control cell fate upon acute and/or chronic stress.
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Affiliation(s)
- Ilaria Pontisso
- U1282 “Calcium Signaling and Microbial Infections”, Institut de Biologie Intégrative de la Cellule (I2BC)—Université Paris-Saclay, Gif-Sur-Yvette 91190, France
| | - Roberto Ornelas-Guevara
- Unit of Theoretical Chronobiology, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
| | - Eric Chevet
- Inserm U1242 Université de Rennes, 35000 Rennes, France
- Centre de Lutte Contre le Cancer Eugène Marquis, 35042 Rennes, France
| | - Laurent Combettes
- U1282 “Calcium Signaling and Microbial Infections”, Institut de Biologie Intégrative de la Cellule (I2BC)—Université Paris-Saclay, Gif-Sur-Yvette 91190, France
| | - Geneviève Dupont
- Unit of Theoretical Chronobiology, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
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2
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Wi D, Park CY. 1,25-dihydroxyvitamin D 3 affects thapsigargin-induced endoplasmic reticulum stress in 3T3-L1 adipocytes. Nutr Res Pract 2024; 18:1-18. [PMID: 38352211 PMCID: PMC10861344 DOI: 10.4162/nrp.2024.18.1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/01/2023] [Accepted: 12/06/2023] [Indexed: 02/16/2024] Open
Abstract
BACKGROUND/OBJECTIVES Endoplasmic reticulum (ER) stress in adipose tissue causes an inflammatory response and leads to metabolic diseases. However, the association between vitamin D and adipose ER stress remains poorly understood. In this study, we investigated whether 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) alleviates ER stress in adipocytes. MATERIALS/METHODS 3T3-L1 cells were treated with different concentrations (i.e., 10-100 nM) of 1,25(OH)2D3 after or during differentiation (i.e., on day 0-7, 3-7, or 7). They were then incubated with thapsigargin (TG, 500 nM) for an additional 24 h to induce ER stress. Next, we measured the mRNA and protein levels of genes involved in unfold protein response (UPR) and adipogenesis using real-time polymerase chain reaction and western blotting and quantified the secreted protein levels of pro-inflammatory cytokines. Finally, the mRNA levels of UPR pathway genes were measured in adipocytes transfected with siRNA-targeting Vdr. RESULTS Treatment with 1,25(OH)2D3 during various stages of adipocyte differentiation significantly inhibited ER stress induced by TG. In fully differentiated 3T3-L1 adipocytes, 1,25(OH)2D3 treatment suppressed mRNA levels of Ddit3, sXbp1, and Atf4 and decreased the secretion of monocyte chemoattractant protein-1, interleukin-6, and tumor necrosis factor-α. However, downregulation of the mRNA levels of Ddit3, sXbp1, and Atf4 following 1,25(OH)2D3 administration was not observed in Vdr-knockdown adipocytes. In addition, exposure of 3T3-L1 preadipocytes to 1,25(OH)2D3 inhibited transcription of Ddit3, sXbp1, Atf4, Bip, and Atf6 and reduced the p-alpha subunit of translation initiation factor 2 (eIF2α)/eIF2α and p-protein kinase RNA-like ER kinase (PERK)/PERK protein ratios. Furthermore, 1,25(OH)2D3 treatment before adipocyte differentiation reduced adipogenesis and the mRNA levels of adipogenic genes. CONCLUSIONS Our data suggest that 1,25(OH)2D3 prevents TG-induced ER stress and inflammatory responses in mature adipocytes by downregulating UPR signaling via binding with Vdr. In addition, the inhibition of adipogenesis by vitamin D may contribute to the reduction of ER stress in adipocytes.
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Affiliation(s)
- Dain Wi
- Department of Food & Nutrition, College of Health Science, The University of Suwon, Hwaseong 18323, Korea
| | - Chan Yoon Park
- Department of Food & Nutrition, College of Health Science, The University of Suwon, Hwaseong 18323, Korea
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3
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Bjorkman SH, Marti A, Jena J, García-Peña LM, Weatherford ET, Kato K, Koneru J, Chen J, Sood A, Potthoff MJ, Adams CM, Abel ED, Pereira RO. ATF4 expression in thermogenic adipocytes is required for cold-induced thermogenesis in mice via FGF21-independent mechanisms. Sci Rep 2024; 14:1563. [PMID: 38238383 PMCID: PMC10796914 DOI: 10.1038/s41598-024-52004-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/12/2024] [Indexed: 01/22/2024] Open
Abstract
In brown adipose tissue (BAT), short-term cold exposure induces the activating transcription factor 4 (ATF4), and its downstream target fibroblast growth factor 21 (FGF21). Induction of ATF4 in BAT in response to mitochondrial stress is required for thermoregulation, partially by increasing FGF21 expression. In the present study, we tested the hypothesis that Atf4 and Fgf21 induction in BAT are both required for BAT thermogenesis under physiological stress by generating mice selectively lacking either Atf4 (ATF4 BKO) or Fgf21 (FGF21 BKO) in UCP1-expressing adipocytes. After 3 days of cold exposure, core body temperature was significantly reduced in ad-libitum-fed ATF4 BKO mice, which correlated with Fgf21 downregulation in brown and beige adipocytes, and impaired browning of white adipose tissue. Conversely, despite having reduced browning, FGF21 BKO mice had preserved core body temperature after cold exposure. Mechanistically, ATF4, but not FGF21, regulates amino acid import and metabolism in response to cold, likely contributing to BAT thermogenic capacity under ad libitum-fed conditions. Importantly, under fasting conditions, both ATF4 and FGF21 were required for thermogenesis in cold-exposed mice. Thus, ATF4 regulates BAT thermogenesis under fed conditions likely in a FGF21-independent manner, in part via increased amino acid uptake and metabolism.
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Affiliation(s)
- Sarah H Bjorkman
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
- Department of Obstetrics and Gynecology, Reproductive Endocrinology and Infertility, University of Iowa Hospital and Clinics, Iowa City, IA, USA
| | - Alex Marti
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Jayashree Jena
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Luis Miguel García-Peña
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Eric T Weatherford
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Kevin Kato
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Jivan Koneru
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Jason Chen
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Ayushi Sood
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Matthew J Potthoff
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Christopher M Adams
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
- Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - E Dale Abel
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Renata O Pereira
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA.
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Hsu MF, Ito Y, Singh JP, Hsu SF, Wells A, Jen KY, Meng TC, Haj FG. Protein tyrosine phosphatase 1B is a regulator of alpha-actinin4 in the glomerular podocyte. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119590. [PMID: 37730132 PMCID: PMC11060668 DOI: 10.1016/j.bbamcr.2023.119590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/22/2023]
Abstract
Glomerular podocytes are instrumental for the barrier function of the kidney, and podocyte injury contributes to proteinuria and the deterioration of renal function. Protein tyrosine phosphatase 1B (PTP1B) is an established metabolic regulator, and the inactivation of this phosphatase mitigates podocyte injury. However, there is a paucity of data regarding the substrates that mediate PTP1B actions in podocytes. This study aims to uncover novel substrates of PTP1B in podocytes and validate a leading candidate. To this end, using substrate-trapping and mass spectroscopy, we identified putative substrates of this phosphatase and investigated the actin cross-linking cytoskeletal protein alpha-actinin4. PTP1B and alpha-actinin4 co-localized in murine and human glomeruli and transiently transfected E11 podocyte cells. Additionally, podocyte PTP1B deficiency in vivo and culture was associated with elevated tyrosine phosphorylation of alpha-actinin4. Conversely, reconstitution of the knockdown cells with PTP1B attenuated alpha-actinin4 tyrosine phosphorylation. We demonstrated co-association between alpha-actinin4 and the PTP1B substrate-trapping mutant, which was enhanced upon insulin stimulation and disrupted by vanadate, consistent with an enzyme-substrate interaction. Moreover, we identified alpha-actinin4 tandem tyrosine residues 486/487 as mediators of its interaction with PTP1B. Furthermore, knockdown studies in E11 cells suggest that PTP1B and alpha-actinin4 are modulators of podocyte motility. These observations indicate that PTP1B and alpha-actinin4 are likely interacting partners in a signaling node that modulates podocyte function. Targeting PTP1B and plausibly this one of its substrates may represent a new therapeutic approach for podocyte injury that warrants additional investigation.
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Affiliation(s)
- Ming-Fo Hsu
- Department of Nutrition, University of California Davis, Davis, CA, USA
| | - Yoshihiro Ito
- Department of Nutrition, University of California Davis, Davis, CA, USA
| | - Jai Prakash Singh
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - Shu-Fang Hsu
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - Alan Wells
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Kuang-Yu Jen
- Department of Pathology and Laboratory Medicine, University of California Davis, Sacramento, CA, USA
| | - Tzu-Ching Meng
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - Fawaz G Haj
- Department of Nutrition, University of California Davis, Davis, CA, USA; Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Internal Medicine, University of California Davis, Sacramento, CA, USA.
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5
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Bjorkman SH, Marti A, Jena J, Garcia Pena LM, Weatherford ET, Kato K, Koneru J, Chen J, Sood A, Potthoff MJ, Adams CM, Abel ED, Pereira RO. ATF4 Expression in Thermogenic Adipocytes is Required for Cold-Induced Thermogenesis in Mice via FGF21-Independent Mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.09.531964. [PMID: 36945390 PMCID: PMC10028960 DOI: 10.1101/2023.03.09.531964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
In brown adipose tissue (BAT), short-term cold exposure induces the activating transcription factor 4 (ATF4), and its downstream target fibroblast growth factor 21 (FGF21). Induction of ATF4 in BAT in response to mitochondrial stress is required for thermoregulation, partially via upregulation of FGF21. In the present study, we tested the hypothesis that Atf4 and Fgf21 induction in BAT are both required for BAT thermogenesis by generating mice selectively lacking either Atf4 ( ATF4 BKO ) or Fgf21 (FGF21 BKO) in UCP1-expressing adipocytes. After 3 days of cold exposure, core body temperature was significantly reduced in ad-libitum -fed ATF4 BKO mice, which correlated with Fgf21 downregulation in brown and beige adipocytes, and impaired browning of white adipose tissue (WAT). Conversely, despite having reduced browning, FGF21 BKO mice had preserved core body temperature after cold exposure. Mechanistically, ATF4, but not FGF21, regulates amino acid import and metabolism in response to cold, likely contributing to BAT thermogenic capacity under ad libitum -fed conditions. Importantly, under fasting conditions, both ATF4 and FGF21 were required for thermogenesis in cold-exposed mice. Thus, ATF4 regulates BAT thermogenesis by activating amino acid metabolism in BAT in a FGF21-independent manner.
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6
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Ssu72 phosphatase is essential for thermogenic adaptation by regulating cytosolic translation. Nat Commun 2023; 14:1097. [PMID: 36841836 PMCID: PMC9968297 DOI: 10.1038/s41467-023-36836-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 02/20/2023] [Indexed: 02/27/2023] Open
Abstract
Brown adipose tissue (BAT) plays a pivotal role in maintaining body temperature and energy homeostasis. BAT dysfunction is associated with impaired metabolic health. Here, we show that Ssu72 phosphatase is essential for mRNA translation of genes required for thermogenesis in BAT. Ssu72 is found to be highly expressed in BAT among adipose tissue depots, and the expression level of Ssu72 is increased upon acute cold exposure. Mice lacking adipocyte Ssu72 exhibit cold intolerance during acute cold exposure. Mechanistically, Ssu72 deficiency alters cytosolic mRNA translation program through hyperphosphorylation of eIF2α and reduces translation of mitochondrial oxidative phosphorylation (OXPHOS) subunits, resulting in mitochondrial dysfunction and defective thermogenesis in BAT. In addition, metabolic dysfunction in Ssu72-deficient BAT returns to almost normal after restoring Ssu72 expression. In summary, our findings demonstrate that cold-responsive Ssu72 phosphatase is involved in cytosolic translation of key thermogenic effectors via dephosphorylation of eIF2α in brown adipocytes, providing insights into metabolic benefits of Ssu72.
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7
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Toxoplasma Shelph, a Phosphatase Located in the Parasite Endoplasmic Reticulum, Is Required for Parasite Virulence. mSphere 2022; 7:e0035022. [PMID: 36326242 PMCID: PMC9769683 DOI: 10.1128/msphere.00350-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Toxoplasma gondii is a single-celled parasitic eukaryote that evolved to successfully propagate in any nucleated cell. As with any other eukaryote, its life cycle is regulated by signaling pathways controlled by kinases and phosphatases. T. gondii encodes an atypical bacterial-like phosphatase absent from mammalian genomes, named Shelph, after its first identification in the psychrophilic bacterium Schewanella sp. Here, we demonstrate that Toxoplasma Shelph is an active phosphatase localized in the parasite endoplasmic reticulum. The phenotyping of a shelph knockout (KO) line showed a minor impairment in invasion on human fibroblasts, while the other steps of the parasite lytic cycle were not affected. In contrast with Plasmodium ortholog Shelph1, this invasion deficiency was not correlated with any default in the biogenesis of secretory organelles. However, Shelph-KO parasites displayed a much-pronounced defect in virulence in vivo. These phenotypes could be rescued by genetic complementation, thus supporting an important function for Shelph in the context of a natural infection. IMPORTANCE Toxoplasma gondii belongs to the Apicomplexa phylum, which comprises more than 5,000 species, among which is Plasmodium falciparum, the notorious agent of human malaria. Intriguingly, the Apicomplexa genomes encode at least one phosphatase closely related to the bacterial Schewanella phosphatase, or Shelph. To better understand the importance of these atypical bacterial enzymes in eukaryotic parasites, we undertook the functional characterization of T. gondii Shelph. Our results uncovered its subcellular localization and its enzymatic activity, revealed its subtle involvement during the tachyzoite invasion step of the lytic cycle, and more importantly, highlighted a critical requirement of this phosphatase for parasite propagation in mice. Overall, this study revealed an unexpected role for T. gondii Shelph in the maintenance of parasite virulence in vivo.
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8
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Barahona I, Rada P, Calero-Pérez S, Grillo-Risco R, Pereira L, Soler-Vázquez MC, LaIglesia LM, Moreno-Aliaga MJ, Herrero L, Serra D, García-Monzon C, González-Rodriguez Á, Balsinde J, García-García F, Valdecantos MP, Valverde ÁM. Ptpn1 deletion protects oval cells against lipoapoptosis by favoring lipid droplet formation and dynamics. Cell Death Differ 2022; 29:2362-2380. [PMID: 35681014 PMCID: PMC9751306 DOI: 10.1038/s41418-022-01023-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 05/17/2022] [Accepted: 05/17/2022] [Indexed: 01/31/2023] Open
Abstract
Activation of oval cells (OCs) has been related to hepatocyte injury during chronic liver diseases including non-alcoholic fatty liver disease (NAFLD). However, OCs plasticity can be affected under pathological environments. We previously found protection against hepatocyte cell death by inhibiting protein tyrosine phosphatase 1B (PTP1B). Herein, we investigated the molecular and cellular processes involved in the lipotoxic susceptibility in OCs expressing or not PTP1B. Palmitic acid (PA) induced apoptotic cell death in wild-type (Ptpn1+/+) OCs in parallel to oxidative stress and impaired autophagy. This lipotoxic effect was attenuated in OCs lacking Ptpn1 that showed upregulated antioxidant defences, increased unfolded protein response (UPR) signaling, higher endoplasmic reticulum (ER) content and elevated stearoyl CoA desaturase (Scd1) expression and activity. These effects in Ptpn1-/- OCs concurred with an active autophagy, higher mitochondrial efficiency and a molecular signature of starvation, favoring lipid droplet (LD) formation and dynamics. Autophagy blockade in Ptpn1-/- OCs reduced Scd1 expression, mitochondrial fitness, LD formation and restored lipoapoptosis, an effect also recapitulated by Scd1 silencing. PTP1B immunostaining was detected in OCs from mouse liver and, importantly, LDs were found in OCs from Ptpn1-/- mice with NAFLD. In conclusion, we demonstrated that Ptpn1 deficiency restrains lipoapoptosis in OCs through a metabolic rewiring towards a "starvation-like" fate, favoring autophagy, mitochondrial fitness and LD formation. Dynamic LD-lysosomal interations likely ensure lipid recycling and, overall, these adaptations protect against lipotoxicity. The identification of LDs in OCs from Ptpn1-/- mice with NAFLD opens therapeutic perspectives to ensure OC viability and plasticity under lipotoxic liver damage.
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Affiliation(s)
- Inés Barahona
- Instituto de Investigaciones Biomédicas Alberto Sols (Centro Mixto CSIC-UAM), 28029, Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 28029, Madrid, Spain
| | - Patricia Rada
- Instituto de Investigaciones Biomédicas Alberto Sols (Centro Mixto CSIC-UAM), 28029, Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 28029, Madrid, Spain
| | - Silvia Calero-Pérez
- Instituto de Investigaciones Biomédicas Alberto Sols (Centro Mixto CSIC-UAM), 28029, Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 28029, Madrid, Spain
| | - Ruben Grillo-Risco
- Bioinformatics and Biostatistics Unit, Principe Felipe Research Center (CIPF), 46012, Valencia, Spain
| | - Laura Pereira
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 28029, Madrid, Spain
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), 47003, Valladolid, Spain
| | - M Carmen Soler-Vázquez
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, 08028, Barcelona, Spain
| | - Laura María LaIglesia
- University of Navarra, Center for Nutrition Research and Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, 31008, Pamplona, Spain
| | - María J Moreno-Aliaga
- University of Navarra, Center for Nutrition Research and Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, 31008, Pamplona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28029, Madrid, Spain
- IdiSNA, Navarra Institute for Health Research, 31008, Pamplona, Spain
| | - Laura Herrero
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, 08028, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - Dolors Serra
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, 08028, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - Carmelo García-Monzon
- Unidad de Investigación, Hospital Universitario Santa Cristina, Instituto de Investigación Sanitaria del Hospital Universitario de La Princesa, 28009, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), 28029, Madrid, Spain
| | - Águeda González-Rodriguez
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 28029, Madrid, Spain
- Unidad de Investigación, Hospital Universitario Santa Cristina, Instituto de Investigación Sanitaria del Hospital Universitario de La Princesa, 28009, Madrid, Spain
- Instituto de Investigaciones Biomédicas Alberto Sols (Centro Mixto CSIC-UAM), 28029, Madrid, Spain
| | - Jesús Balsinde
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 28029, Madrid, Spain
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), 47003, Valladolid, Spain
| | - Francisco García-García
- Bioinformatics and Biostatistics Unit, Principe Felipe Research Center (CIPF), 46012, Valencia, Spain
| | - M Pilar Valdecantos
- Instituto de Investigaciones Biomédicas Alberto Sols (Centro Mixto CSIC-UAM), 28029, Madrid, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 28029, Madrid, Spain.
| | - Ángela M Valverde
- Instituto de Investigaciones Biomédicas Alberto Sols (Centro Mixto CSIC-UAM), 28029, Madrid, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 28029, Madrid, Spain.
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9
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Correia C, Wang QD, Linhardt G, Carlsson LG, Ulfenborg B, Walentinsson A, Rydén-Markinhutha K, Behrendt M, Wikström J, Sartipy P, Jennbacken K, Synnergren J. Unraveling the Metabolic Derangements Occurring in Non-infarcted Areas of Pig Hearts With Chronic Heart Failure. Front Cardiovasc Med 2021; 8:753470. [PMID: 34722683 PMCID: PMC8548620 DOI: 10.3389/fcvm.2021.753470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: After myocardial infarction (MI), the non-infarcted left ventricle (LV) ensures appropriate contractile function of the heart. Metabolic disturbance in this region greatly exacerbates post-MI heart failure (HF) pathology. This study aimed to provide a comprehensive understanding of the metabolic derangements occurring in the non-infarcted LV that could trigger cardiovascular deterioration. Methods and Results: We used a pig model that progressed into chronic HF over 3 months following MI induction. Integrated gene and metabolite signatures revealed region-specific perturbations in amino acid- and lipid metabolism, insulin signaling and, oxidative stress response. Remote LV, in particular, showed impaired glutamine and arginine metabolism, altered synthesis of lipids, glucose metabolism disorder, and increased insulin resistance. LPIN1, PPP1R3C, PTPN1, CREM, and NR0B2 were identified as the main effectors in metabolism dysregulation in the remote zone and were found differentially expressed also in the myocardium of patients with ischemic and/or dilated cardiomyopathy. In addition, a simultaneous significant decrease in arginine levels and altered PRCP, PTPN1, and ARF6 expression suggest alterations in vascular function in remote area. Conclusions: This study unravels an array of dysregulated genes and metabolites putatively involved in maladaptive metabolic and vascular remodeling in the non-infarcted myocardium and may contribute to the development of more precise therapies to mitigate progression of chronic HF post-MI.
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Affiliation(s)
- Cláudia Correia
- Systems Biology Research Center, Translational Bioinformatics Research Group, School of Biosciences, University of Skövde, Skövde, Sweden.,Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Qing-Dong Wang
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Gunilla Linhardt
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Leif G Carlsson
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Benjamin Ulfenborg
- Systems Biology Research Center, Translational Bioinformatics Research Group, School of Biosciences, University of Skövde, Skövde, Sweden
| | - Anna Walentinsson
- Translational Science & Experimental Medicine, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Katarina Rydén-Markinhutha
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Margareta Behrendt
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Johannes Wikström
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Peter Sartipy
- Systems Biology Research Center, Translational Bioinformatics Research Group, School of Biosciences, University of Skövde, Skövde, Sweden.,Late-Stage Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Karin Jennbacken
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Jane Synnergren
- Systems Biology Research Center, Translational Bioinformatics Research Group, School of Biosciences, University of Skövde, Skövde, Sweden
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10
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Bhattarai KR, Kim HK, Chaudhary M, Ur Rashid MM, Kim J, Kim HR, Chae HJ. TMBIM6 regulates redox-associated posttranslational modifications of IRE1α and ER stress response failure in aging mice and humans. Redox Biol 2021; 47:102128. [PMID: 34562874 PMCID: PMC8476450 DOI: 10.1016/j.redox.2021.102128] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/30/2021] [Accepted: 09/06/2021] [Indexed: 12/25/2022] Open
Abstract
Age-associated persistent ER stress is the result of declining chaperone systems of the ER that reduces cellular functions, induces apoptosis, and leads to age-related diseases. This study investigated the previously unknown regulatory mechanism of TMBIM6 during age-associated hepatic abnormalities. Wild-type (WT) and the TMBIM6 knockout (TMBIM6−/−) mice liver, human liver samples from different age groups were used to demonstrate the effect of physiological aging on liver. For TMBIM6 rescue experiments, TMBIM6−/− old mice and stable human hepatic cell lines expressing TMBIM 6 were used to study the functional role of TMBIM6 on aging-associated steatosis and its associated mechanisms. In aging humans and mice, we observed declined expression of TMBIM6 and aberrant UPR expression, which were associated with high hepatic lipid accumulation. During aging, TMBIM6-deficient mice had increased senescence than their WT counterparts. We identified redox-mediated posttranslational modifications of IRE1α such as S-nitrosylation and sulfonation were higher in TMBIM6-deficient aging mice and humans, which impaired the ER stress response signaling. Sulfonation of IRE1α enhanced regulated IRE1α-dependent decay (RIDD) activity inducing TMBIM6 decay, whereas S-nitrosylation of IRE1α inhibited XBP1 splicing enhancing the cell death. Moreover, the degradation of miR-338-3p by strong IRE1α cleavage activity enhanced the expression of PTP1B, resulting in diminishing phosphorylation of PERK. The re-expression of TMBIM6 reduced IRE1α modifications, preserved ER homeostasis, reduced senescence and senescence-associated lipid accumulation in human hepatic cells and TMBIM6-depleted mice. S-nitrosylation or sulfonation of IRE1α and its controller, the TMBIM6, might be the potential therapeutic targets for maintaining ER homeostasis in aging and aging-associated liver diseases. TMBIM6 is downregulated in fatty degeneration, and in aging human and mouse liver. TMBIM6 deficiency induces ER stress response failure and cell death and increases age-associated steatosis. TMBIM6 regulates redox-mediated cysteine modifications such as S-nitrosylation and sulfonation of IRE1α. IRE1α-SNO inhibits XBP1 splicing, whereas IRE1α-SO3H enhances RIDD activity inducing TMBIM6 decay. TMBIM6 overexpression attenuates hepatic steatosis by regulating ER stress and cysteine modifications caused by aging.
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Affiliation(s)
- Kashi Raj Bhattarai
- School of Pharmacy and Institute of New Drug Development, Jeonbuk National University, 54896, Jeonju, Republic of Korea; Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 38105, Memphis, TN, USA
| | - Hyun-Kyoung Kim
- School of Pharmacy and Institute of New Drug Development, Jeonbuk National University, 54896, Jeonju, Republic of Korea
| | - Manoj Chaudhary
- Department of Pharmacology and Institute of New Drug Development, Jeonbuk National University Medical School, 54896, Jeonju, Republic of Korea
| | - Mohammad Mamun Ur Rashid
- Department of Pharmacology and Institute of New Drug Development, Jeonbuk National University Medical School, 54896, Jeonju, Republic of Korea
| | - Jisun Kim
- School of Pharmacy and Institute of New Drug Development, Jeonbuk National University, 54896, Jeonju, Republic of Korea
| | - Hyung-Ryong Kim
- Department of Dental Pharmacology, College of Dentistry, Jeonbuk National University, Jeonju, 54896, Republic of Korea.
| | - Han-Jung Chae
- School of Pharmacy and Institute of New Drug Development, Jeonbuk National University, 54896, Jeonju, Republic of Korea.
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11
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Zhu Y, Yu J, Gong J, Shen J, Ye D, Cheng D, Xie Z, Zeng J, Xu K, Shen J, Zhou H, Weng Y, Pan J, Zhan R. PTP1B inhibitor alleviates deleterious microglial activation and neuronal injury after ischemic stroke by modulating the ER stress-autophagy axis via PERK signaling in microglia. Aging (Albany NY) 2021; 13:3405-3427. [PMID: 33495405 PMCID: PMC7906217 DOI: 10.18632/aging.202272] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 11/06/2020] [Indexed: 12/17/2022]
Abstract
Cerebral ischemia/reperfusion (IR) after ischemic stroke causes deleterious microglial activation. Protein tyrosine phosphatase 1B (PTP1B) exacerbates neuroinflammation, yet the effect of the inhibition on microglial activation and cerebral IR injury is unknown. A cerebral IR rat model was induced by middle cerebral artery occlusion (MCAO) and reperfusion. The PTP1B inhibitor, sc-222227, was administered intracerebroventricularly. Neurologic deficits, infarct volume, and brain water content were examined. An in vitro oxygen glucose deprivation/reoxygenation (OGD/R) model was established in primary microglia and BV-2 cells. Microglial activation/polarization, endoplasmic reticulum (ER) stress, autophagy, and apoptosis were detected using western blot, immunohistology, ELISA, and real-time PCR. Protein interaction was assessed by a proximity ligation assay. The results showed a significant increase in microglial PTP1B expression after IR injury. Sc-222227 attenuated IR-induced microglial activation, ER stress, and autophagy and promoted M2 polarization. Upon OGD/R, sc-222227 mitigated microglial activation by inhibiting ER stress-dependent autophagy, the effect of which was abolished by PERK activation, and PERK inhibition attenuated microglial activation. The PTP1B-phosphorylated PERK protein interaction was significantly increased after OGD/R, but decreased upon sc-222227 treatment. Finally, sc-222227 mitigated neuronal damage and neurologic deficits after IR injury. Treatment targeting microglial PTP1B might be a potential therapeutic strategy for ischemic stroke treatment.
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Affiliation(s)
- Yu Zhu
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Jianbo Yu
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Jiangbiao Gong
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Jie Shen
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Di Ye
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Dexin Cheng
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Zhikai Xie
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Jianping Zeng
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Kangli Xu
- Emergency Department Trauma Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Jian Shen
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Hengjun Zhou
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Yuxiang Weng
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Jianwei Pan
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Renya Zhan
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
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12
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Winnay JN, Solheim MH, Sakaguchi M, Njølstad PR, Kahn CR. Inhibition of the PI 3-kinase pathway disrupts the unfolded protein response and reduces sensitivity to ER stress-dependent apoptosis. FASEB J 2020; 34:12521-12532. [PMID: 32744782 DOI: 10.1096/fj.202000892r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/07/2020] [Accepted: 07/07/2020] [Indexed: 01/01/2023]
Abstract
Class Ia phosphoinositide 3-kinases (PI3K) are critical mediators of insulin and growth factor action. We have demonstrated that the p85α regulatory subunit of PI3K modulates the unfolded protein response (UPR) by interacting with and regulating the nuclear translocation of XBP-1s, a transcription factor essential for the UPR. We now show that PI3K activity is required for full activation of the UPR. Pharmacological inhibition of PI3K in cells blunts the ER stress-dependent phosphorylation of IRE1α and PERK, decreases induction of ATF4, CHOP, and XBP-1 and upregulates UPR target genes. Cells expressing a human p85α mutant (R649W) previously shown to inhibit PI3K, exhibit decreased activation of IRE1α and PERK and reduced induction of CHOP and ATF4. Pharmacological inhibition of PI3K, overexpression of a mutant of p85α that lacks the ability to interact with the p110α catalytic subunit (∆p85α) or expression of mutant p85α (R649W) in vivo, decreased UPR-dependent induction of ER stress response genes. Acute tunicamycin treatment of R649W+/- mice revealed reduced induction of UPR target genes in adipose tissue, whereas chronic tunicamycin exposure caused sustained increases in UPR target genes in adipose tissue. Finally, R649W+/- cells exhibited a dramatic resistance to ER stress-dependent apoptosis. These data suggest that PI3K pathway dysfunction causes ER stress that may drive the pathogenesis of several diseases including Type 2 diabetes and various cancers.
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Affiliation(s)
| | - Marie H Solheim
- Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA.,Department of Clinical Science, KG Jebsen Center for Diabetes Research, University of Bergen, Bergen, Norway
| | - Masaji Sakaguchi
- Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA.,Department of Metabolic Medicine, Kumamoto University, Kumamoto, Japan
| | - Pål R Njølstad
- Department of Clinical Science, KG Jebsen Center for Diabetes Research, University of Bergen, Bergen, Norway.,Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - C Ronald Kahn
- Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
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13
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Flicker D, Sancak Y, Mick E, Goldberger O, Mootha VK. Exploring the In Vivo Role of the Mitochondrial Calcium Uniporter in Brown Fat Bioenergetics. Cell Rep 2020; 27:1364-1375.e5. [PMID: 31042465 PMCID: PMC7231522 DOI: 10.1016/j.celrep.2019.04.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 09/28/2018] [Accepted: 04/02/2019] [Indexed: 12/21/2022] Open
Abstract
The mitochondrial calcium uniporter has been proposed to coordinate the organelle’s energetics with calcium signaling. Uniporter current has previously been reported to be extremely high in brown adipose tissue (BAT), yet it remains unknown how the uniporter contributes to BAT physiology. Here, we report the generation and characterization of a mouse model lacking Mcu, the pore forming subunit of the uniporter, specifically in BAT (BAT-Mcu-KO). BAT-Mcu-KO mice lack uniporter-based calcium uptake in BAT mitochondria but exhibit unaffected cold tolerance, diet-induced obesity, and transcriptional response to cold in BAT. Unexpectedly, we found in wild-type animals that cold powerfully activates the ATF4-dependent integrated stress response (ISR) in BAT and up-regulates circulating FGF21 and GDF15, raising the hypothesis that the ISR partly underlies the pleiotropic effects of BAT on systemic metabolism. Our study demonstrates that the uniporter is largely dispensable for BAT thermogenesis and demonstrates activation of the ISR in BAT in response to cold. Flicker et al. generate a mouse lacking mitochondrial calcium uniporter activity in brown fat. They show that the uniporter is dispensable for brown fat bioenergetics. Unexpectedly, they find that in wild type animals, cold stress induces ATF4 signaling in normal brown fat, suggesting a mechanism for cold-induced GDF15 and FGF21 elevation.
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Affiliation(s)
- Daniel Flicker
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA
| | - Yasemin Sancak
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA.
| | - Eran Mick
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA
| | - Olga Goldberger
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA.
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14
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The Role of Protein Tyrosine Phosphatase (PTP)-1B in Cardiovascular Disease and Its Interplay with Insulin Resistance. Biomolecules 2019; 9:biom9070286. [PMID: 31319588 PMCID: PMC6680919 DOI: 10.3390/biom9070286] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/06/2019] [Accepted: 07/12/2019] [Indexed: 12/19/2022] Open
Abstract
Endothelial dysfunction is a key feature of cardiovascular disorders associated with obesity and diabetes. Several studies identified protein tyrosine phosphatase (PTP)-1B, a member of the PTP superfamily, as a major negative regulator for insulin receptor signaling and a novel molecular player in endothelial dysfunction and cardiovascular disease. Unlike other anti-diabetic approaches, genetic deletion or pharmacological inhibition of PTP1B was found to improve glucose homeostasis and insulin signaling without causing lipid buildup in the liver, which represents an advantage over existing therapies. Furthermore, PTP1B was reported to contribute to cardiovascular disturbances, at various molecular levels, which places this enzyme as a unique single therapeutic target for both diabetes and cardiovascular disorders. Synthesizing selective small molecule inhibitors for PTP1B is faced with multiple challenges linked to its similarity of sequence with other PTPs; however, overcoming these challenges would pave the way for novel approaches to treat diabetes and its concurrent cardiovascular complications. In this review article, we summarized the major roles of PTP1B in cardiovascular disease with special emphasis on endothelial dysfunction and its interplay with insulin resistance. Furthermore, we discussed some of the major challenges hindering the synthesis of selective inhibitors for PTP1B.
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15
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Nemecz M, Constantin A, Dumitrescu M, Alexandru N, Filippi A, Tanko G, Georgescu A. The Distinct Effects of Palmitic and Oleic Acid on Pancreatic Beta Cell Function: The Elucidation of Associated Mechanisms and Effector Molecules. Front Pharmacol 2019; 9:1554. [PMID: 30719005 PMCID: PMC6348268 DOI: 10.3389/fphar.2018.01554] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 12/20/2018] [Indexed: 12/13/2022] Open
Abstract
In this study, we aimed to identify the mechanisms underlying the different effects of palmitic acid and oleic acid on human pancreatic beta cell function. To address this problem, the oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis and their mediator molecules have been investigated in the insulin releasing beta cells exposed to palmitic and/or oleic acid. Herein, we have demonstrated that in cultured 1.1B4 beta cells oleic acid promotes neutral lipid accumulation and insulin secretion, whereas palmitic acid is poorly incorporated into triglyceride and it does not stimulate insulin secretion from human pancreatic islets at physiologically glucose concentrations. In addition, palmitic acid caused: (1) oxidative stress through a mechanism involving increases in ROS production and MMP-2 protein expression/gelatinolytic activity associated with down-regulation of SOD2 protein; (2) endoplasmic reticulum stress by up-regulation of chaperone BiP protein and unfolded protein response (UPR) transcription factors (eIF2α, ATF6, XBP1u proteins) and by PTP-1B down-regulation in both mRNA and protein levels; (3) inflammation through enhanced synthesis of proinflammatory cytokines (IL6, IL8 proteins); and (4) apoptosis by enforced proteic expression of CHOP multifunctional transcription factor. Oleic acid alone had opposite effects due to its different capacity of controlling these metabolic pathways, in particular by reduction of the ROS levels and MMP-2 activity, down-regulation of BiP, eIF2α, ATF6, XBP1u, CHOP, IL6, IL8 and by SOD2 and PTP-1B overexpression. The supplementation of saturated palmitic acid with the monounsaturated oleic acid reversed the negative effects of palmitic acid alone regulating insulin secretion from pancreatic beta cells through ROS, MMP-2, ATF6, XBP1u, IL8 reduction and SOD2, PTP-1B activation. Our findings have shown the protective action of oleic acid against palmitic acid on beta cell lipotoxicity through promotion of triglyceride accumulation and insulin secretion and regulation of some effector molecules involved in oxidative stress, endoplasmic reticulum stress, inflammation and apoptosis.
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Affiliation(s)
- Miruna Nemecz
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Alina Constantin
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Madalina Dumitrescu
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Nicoleta Alexandru
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Alexandru Filippi
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Gabriela Tanko
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Adriana Georgescu
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
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16
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Koh JH, Wang L, Beaudoin-Chabot C, Thibault G. Lipid bilayer stress-activated IRE-1 modulates autophagy during endoplasmic reticulum stress. J Cell Sci 2018; 131:jcs.217992. [PMID: 30333136 DOI: 10.1242/jcs.217992] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 10/01/2018] [Indexed: 12/14/2022] Open
Abstract
Metabolic disorders, such as non-alcoholic fatty liver disease (NAFLD), are emerging as epidemics that affect the global population. One facet of these disorders is attributed to the disturbance of membrane lipid composition. Perturbation of endoplasmic reticulum (ER) homeostasis through alteration in membrane phospholipids activates the unfolded protein response (UPR) and causes dramatic transcriptional and translational changes in the cell. To restore cellular homeostasis, the three highly conserved UPR transducers ATF6, IRE1 (also known as ERN1 in mammals) and PERK (also known as EIF2AK3 in mammals) mediate adaptive responses upon ER stress. The homeostatic UPR cascade is well characterised under conditions of proteotoxic stress, but much less so under lipid bilayer stress-induced UPR. Here, we show that disrupted phosphatidylcholine (PC) synthesis in Caenorhabditis elegans causes lipid bilayer stress, lipid droplet accumulation and ER stress induction. Transcriptional profiling of PC-deficient worms revealed a unique subset of genes regulated in a UPR-dependent manner that is independent from proteotoxic stress. Among these, we show that autophagy is modulated through the conserved IRE-1-XBP-1 axis, strongly suggesting of the importance of autophagy in maintaining cellular homeostasis during the lipid bilayer stress-induced UPR.
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Affiliation(s)
- Jhee Hong Koh
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Lei Wang
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | | | - Guillaume Thibault
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
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17
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Thiebaut PA, Delile E, Coquerel D, Brunel JM, Renet S, Tamion F, Richard V. Protein tyrosine phosphatase 1B regulates endothelial endoplasmic reticulum stress; role in endothelial dysfunction. Vascul Pharmacol 2018; 109:36-44. [DOI: 10.1016/j.vph.2018.05.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/23/2018] [Accepted: 05/30/2018] [Indexed: 12/15/2022]
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18
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Carmichael JC, Yokota H, Craven RC, Schmitt A, Wills JW. The HSV-1 mechanisms of cell-to-cell spread and fusion are critically dependent on host PTP1B. PLoS Pathog 2018; 14:e1007054. [PMID: 29742155 PMCID: PMC5962101 DOI: 10.1371/journal.ppat.1007054] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/21/2018] [Accepted: 04/25/2018] [Indexed: 01/01/2023] Open
Abstract
All herpesviruses have mechanisms for passing through cell junctions, which exclude neutralizing antibodies and offer a clear path to neighboring, uninfected cells. In the case of herpes simplex virus type 1 (HSV-1), direct cell-to-cell transmission takes place between epithelial cells and sensory neurons, where latency is established. The spreading mechanism is poorly understood, but mutations in four different HSV-1 genes can dysregulate it, causing neighboring cells to fuse to produce syncytia. Because the host proteins involved are largely unknown (other than the virus entry receptor), we were intrigued by an earlier discovery that cells infected with wild-type HSV-1 will form syncytia when treated with salubrinal. A biotinylated derivative of this drug was used to pull down cellular complexes, which were analyzed by mass spectrometry. One candidate was a protein tyrosine phosphatase (PTP1B), and although it ultimately proved not to be the target of salubrinal, it was found to be critical for the mechanism of cell-to-cell spread. In particular, a highly specific inhibitor of PTP1B (CAS 765317-72-4) blocked salubrinal-induced fusion, and by itself resulted in a dramatic reduction in the ability of HSV-1 to spread in the presence of neutralizing antibodies. The importance of this phosphatase was confirmed in the absence of drugs by using PTP1B-/- cells. Importantly, replication assays showed that virus titers were unaffected when PTP1B was inhibited or absent. Only cell-to-cell spread was altered. We also examined the effects of salubrinal and the PTP1B inhibitor on the four Syn mutants of HSV-1, and strikingly different responses were found. That is, both drugs individually enhanced fusion for some mutants and reduced fusion for others. PTP1B is the first host factor identified to be specifically required for cell-to-cell spread, and it may be a therapeutic target for preventing HSV-1 reactivation disease. It is estimated that 67% of the global population is infected with herpes simplex virus type 1 (HSV-1). This virus resides in sensory neurons in a quiescent state but periodically reactivates, producing virus particles that travel down the axon to infect epithelial cells of the skin, where it can be transmitted to additional people. To avoid neutralizing antibodies, herpesviruses have evolved mechanisms for moving directly from one cell to another through their sites of intimate contact; however, the mechanism of cell-to-cell spread is poorly understood. Studies of HSV-1 mutants have implicated numerous viral proteins, but the necessary cellular factors are unknown except for the one that the virus uses to enter cells. Our experiments have identified a cellular enzyme (PTP1B, a tyrosine phosphatase) that is dispensable for the production of infectious virions but is critically important for the cell-to-cell spreading mechanism. Promising drugs targeting PTP1B have already been tested in early clinical trials for possible treatment of obesity and type-2 diabetes, and thus, our study may have immediate utility for attenuating HSV-1 reactivation disease in immunocompromised patients.
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Affiliation(s)
- Jillian C. Carmichael
- Department of Microbiology and Immunology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, United States of America
| | - Hiroki Yokota
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States of America
| | - Rebecca C. Craven
- Department of Microbiology and Immunology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, United States of America
| | - Anthony Schmitt
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - John W. Wills
- Department of Microbiology and Immunology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, United States of America
- * E-mail:
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Ito Y, Hsu MF, Bettaieb A, Koike S, Mello A, Calvo-Rubio M, Villalba JM, Haj FG. Protein tyrosine phosphatase 1B deficiency in podocytes mitigates hyperglycemia-induced renal injury. Metabolism 2017; 76:56-69. [PMID: 28987240 PMCID: PMC5690491 DOI: 10.1016/j.metabol.2017.07.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 07/13/2017] [Accepted: 07/31/2017] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Diabetic nephropathy is one of the most devastating complications of diabetes, and growing evidence implicates podocyte dysfunction in disease pathogenesis. The objective of this study was to investigate the contribution of protein tyrosine phosphatase 1B (PTP1B) in podocytes to hyperglycemia-induced renal injury. METHODS To determine the in vivo function of PTP1B in podocytes we generated mice with podocyte-specific PTP1B disruption (hereafter termed pod-PTP1B KO). Kidney functions were determined in control and pod-PTP1B KO mice under normoglycemia and high-fat diet (HFD)- and streptozotocin (STZ)-induced hyperglycemia. RESULTS PTP1B expression increased in murine kidneys following HFD and STZ challenges. Under normoglycemia control and pod-PTP1B KO mice exhibited comparable renal functions. However, podocyte PTP1B disruption attenuated hyperglycemia-induced albuminuria and renal injury and preserved glucose control. Also, podocyte PTP1B disruption was accompanied with improved renal insulin signaling and enhanced autophagy with decreased inflammation and fibrosis. Moreover, the beneficial effects of podocyte PTP1B disruption in vivo were recapitulated in E11 murine podocytes with lentiviral-mediated PTP1B knockdown. Reconstitution of PTP1B in knockdown podocytes reversed the enhanced insulin signaling and autophagy suggesting that they were likely a consequence of PTP1B deficiency. Further, pharmacological attenuation of autophagy in PTP1B knockdown podocytes mitigated the protective effects of PTP1B deficiency. CONCLUSIONS These findings demonstrate that podocyte PTP1B deficiency attenuates hyperglycemia-induced renal damage and suggest that PTP1B may present a therapeutic target in renal injury.
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Affiliation(s)
- Yoshihiro Ito
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States
| | - Ming-Fo Hsu
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States
| | - Ahmed Bettaieb
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States
| | - Shinichiro Koike
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States
| | - Aline Mello
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States
| | - Miguel Calvo-Rubio
- Department of Cell Biology, Physiology and Immunology, Agrifood Campus of International Excellence ceiA3, University of Cordoba, 14014 Cordoba, Spain
| | - Jose M Villalba
- Department of Cell Biology, Physiology and Immunology, Agrifood Campus of International Excellence ceiA3, University of Cordoba, 14014 Cordoba, Spain
| | - Fawaz G Haj
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States; Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, United States; Division of Endocrinology, Diabetes, and Metabolism, Department of Internal Medicine, University of California Davis, Sacramento, CA 95817, United States.
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20
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IRE1α links Nck1 deficiency to attenuated PTP1B expression in HepG2 cells. Cell Signal 2017; 36:79-90. [DOI: 10.1016/j.cellsig.2017.04.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 04/11/2017] [Accepted: 04/23/2017] [Indexed: 12/23/2022]
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21
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Morinda citrifolia Linn. (Noni) and Its Potential in Obesity-Related Metabolic Dysfunction. Nutrients 2017; 9:nu9060540. [PMID: 28587078 PMCID: PMC5490519 DOI: 10.3390/nu9060540] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 03/23/2017] [Accepted: 04/26/2017] [Indexed: 12/13/2022] Open
Abstract
Cultural and economic shifts in the early 19th century led to the rapid development of companies that made good profits from technologically-produced commodities. In this way, some habits changed in society, such as the overconsumption of processed and micronutrient-poor foods and devices that gave rise to a sedentary lifestyle. These factors influenced host-microbiome interactions which, in turn, mediated the etiopathogenesis of “new-era” disorders and diseases, which are closely related, such as obesity, type 2 diabetes mellitus, non-alcoholic fatty liver disease, hypertension, and inflammatory bowel disease, which are characterized by chronic dysregulation of metabolic and immune processes. These pathological conditions require novel and effective therapeutic approaches. Morindacitrifolia (noni) is well known as a traditional healing plant due to its medicinal properties. Thus, many studies have been conducted to understand its bioactive compounds and their mechanisms of action. However, in obesity and obesity-related metabolic (dysfunction) syndrome, other studies are necessary to better elucidate noni’s mechanisms of action, mainly due to the complexity of the pathophysiology of obesity and its metabolic dysfunction. In this review, we summarize not only the clinical effects, but also important cell signaling pathways in in vivo and in vitro assays of potent bioactive compounds present in the noni plant which have been reported in studies of obesity and obesity-associated metabolic dysfunction.
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Jeon YM, Lee S, Kim S, Kwon Y, Kim K, Chung CG, Lee S, Lee SB, Kim HJ. Neuroprotective Effects of Protein Tyrosine Phosphatase 1B Inhibition against ER Stress-Induced Toxicity. Mol Cells 2017; 40:280-290. [PMID: 28359145 PMCID: PMC5424274 DOI: 10.14348/molcells.2017.2320] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/21/2017] [Accepted: 03/22/2017] [Indexed: 12/15/2022] Open
Abstract
Several lines of evidence suggest that endoplasmic reticulum (ER) stress plays a critical role in the pathogenesis of many neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Protein tyrosine phosphatase 1B (PTP1B) is known to regulate the ER stress signaling pathway, but its role in neuronal systems in terms of ER stress remains largely unknown. Here, we showed that rotenone-induced toxicity in human neuroblastoma cell lines and mouse primary cortical neurons was ameliorated by PTP1B inhibition. Moreover, the increase in the level of ER stress markers (eIF2α phosphorylation and PERK phosphorylation) induced by rotenone treatment was obviously suppressed by concomitant PTP1B inhibition. However, the rotenone-induced production of reactive oxygen species (ROS) was not affected by PTP1B inhibition, suggesting that the neuroprotective effect of the PTP1B inhibitor is not associated with ROS production. Moreover, we found that MG132-induced toxicity involving proteasome inhibition was also ameliorated by PTP1B inhibition in a human neuroblastoma cell line and mouse primary cortical neurons. Consistently, downregulation of the PTP1B homologue gene in Drosophila mitigated rotenone- and MG132-induced toxicity. Taken together, these findings indicate that PTP1B inhibition may represent a novel therapeutic approach for ER stress-mediated neurodegenerative diseases.
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Affiliation(s)
- Yu-Mi Jeon
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu 41068,
Korea
| | - Shinrye Lee
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu 41068,
Korea
| | - Seyeon Kim
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu 41068,
Korea
| | - Younghwi Kwon
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu 41068,
Korea
| | - Kiyoung Kim
- Department of Medical Biotechnology, Soonchunhyang University, Asan 31538,
Korea
| | - Chang Geon Chung
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| | - Seongsoo Lee
- Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju 61186,
Korea
| | - Sung Bae Lee
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| | - Hyung-Jun Kim
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu 41068,
Korea
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23
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Thiebaut PA, Besnier M, Gomez E, Richard V. Role of protein tyrosine phosphatase 1B in cardiovascular diseases. J Mol Cell Cardiol 2016; 101:50-57. [DOI: 10.1016/j.yjmcc.2016.09.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 08/31/2016] [Accepted: 09/01/2016] [Indexed: 12/14/2022]
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Bettaieb A, Koike S, Chahed S, Bachaalany S, Griffey S, Sastre J, Haj FG. Pancreatic Protein Tyrosine Phosphatase 1B Deficiency Exacerbates Acute Pancreatitis in Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:2043-2054. [PMID: 27461362 DOI: 10.1016/j.ajpath.2016.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 03/03/2016] [Accepted: 04/06/2016] [Indexed: 12/12/2022]
Abstract
Acute pancreatitis (AP) is a common and devastating gastrointestinal disorder that causes significant morbidity. The disease starts as local inflammation in the pancreas that may progress to systemic inflammation and complications. Protein tyrosine phosphatase 1B (PTP1B) is implicated in inflammatory signaling, but its significance in AP remains unclear. To investigate whether PTP1B may have a role in AP, we used pancreas PTP1B knockout (panc-PTP1B KO) mice and determined the effects of pancreatic PTP1B deficiency on cerulein- and arginine-induced acute pancreatitis. We report that PTP1B protein expression was increased in the early phase of AP in mice and rats. In addition, histological analyses of pancreas samples revealed enhanced features of AP in cerulein-treated panc-PTP1B KO mice compared with controls. Moreover, cerulein- and arginine-induced serum amylase and lipase were significantly higher in panc-PTP1B KO mice compared with controls. Similarly, pancreatic mRNA and serum concentrations of the inflammatory cytokines IL-1B, IL-6, and tumor necrosis factor-α were increased in panc-PTP1B KO mice compared with controls. Furthermore, panc-PTP1B KO mice exhibited enhanced cerulein- and arginine-induced NF-κB inflammatory response accompanied with increased mitogen-activated protein kinases activation and elevated endoplasmic reticulum stress. Notably, these effects were recapitulated in acinar cells treated with a pharmacological inhibitor of PTP1B. These findings reveal a novel role for pancreatic PTP1B in cerulein- and arginine-induced acute pancreatitis.
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Affiliation(s)
- Ahmed Bettaieb
- Department of Nutrition, University of California Davis, Davis, California.
| | - Shinichiro Koike
- Department of Nutrition, University of California Davis, Davis, California
| | - Samah Chahed
- Department of Nutrition, University of California Davis, Davis, California
| | - Santana Bachaalany
- Department of Nutrition, University of California Davis, Davis, California
| | - Stephen Griffey
- Comparative Pathology Laboratory, University of California Davis, Davis, California
| | - Juan Sastre
- Department of Physiology, University of Valencia, Burjasot, Spain
| | - Fawaz G Haj
- Department of Nutrition, University of California Davis, Davis, California; Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of California Davis, Sacramento, California; Comprehensive Cancer Center, University of California Davis, Sacramento, California.
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25
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Han JH, Zhou W, Li W, Tuan PQ, Khoi NM, Thuong PT, Na M, Myung CS. Pentacyclic Triterpenoids from Astilbe rivularis that Enhance Glucose Uptake via the Activation of Akt and Erk1/2 in C2C12 Myotubes. JOURNAL OF NATURAL PRODUCTS 2015; 78:1005-1014. [PMID: 25894669 DOI: 10.1021/np5009174] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Glucose uptake into insulin-sensitive tissues is important for the regulation of blood glucose. This study has investigated whether the pentacyclic triterpenoids substituted with a carboxylic acid at the C-27 position isolated from Astilbe rivularis can enhance glucose uptake and subsequently to also examine their underlying molecular mechanisms. The structure of the new pentacyclic triterpenoid 1 was assigned by spectroscopic data interpretation. To evaluate the activity of compounds 1 and 2, glucose uptake and glucose transporter 4 (GLUT4) translocation were measured in C2C12 myotubes. The C-27-carboxylated triterpenoids 1 and 2 significantly increased basal and insulin-stimulated glucose uptake and GLUT4 translocation to plasma membrane. Both compounds stimulated the phosphorylation of insulin receptor substrate-1 (IRS-1), protein kinase B (Akt), and extracellular signal-regulated kinase 1/2 (Erk1/2). Pretreatment with the Akt inhibitor triciribine or the Erk1/2 inhibitor U0126 decreased the ability of both compounds to enhance basal- and insulin-stimulated glucose uptake and stimulate GLUT4 translocation. These results indicate that compounds 1 and 2 activated both the IRS-1/Akt and Erk1/2 pathways and subsequently stimulated GLUT4 translocation, leading to enhanced glucose uptake. Thus, these observations suggest that C-27-carboxylated-pentacyclic triterpenoids may serve as scaffolds for development as agents for the management of blood glucose levels in disease states such as diabetes.
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Affiliation(s)
| | - Wei Zhou
- §College of Pharmacy, Yanbian University, Yanji 133002, People's Republic of China
| | - Wei Li
- ⊥School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, Republic of Korea
| | - Pham Quoc Tuan
- ∥National Institute of Medicinal Materials, 3B Quang Trung, Hoan Kiem, Hanoi, Vietnam
| | - Nguyen Minh Khoi
- ∥National Institute of Medicinal Materials, 3B Quang Trung, Hoan Kiem, Hanoi, Vietnam
| | - Phuong Thien Thuong
- ∥National Institute of Medicinal Materials, 3B Quang Trung, Hoan Kiem, Hanoi, Vietnam
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Koromilas AE. Roles of the translation initiation factor eIF2α serine 51 phosphorylation in cancer formation and treatment. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:871-80. [PMID: 25497381 DOI: 10.1016/j.bbagrm.2014.12.007] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/03/2014] [Accepted: 12/07/2014] [Indexed: 01/12/2023]
Abstract
Cells respond to various forms of stress by activating anti-proliferative pathways, which allow them to correct the damage caused by stress before re-entering proliferation. If the damage, however, is beyond repair, stressed cells are eliminated from the host by undergoing death. The balance between cell survival and death is essential for cancer formation and is determined by several key pathways that impact on different stages of gene expression. In recent years, it has become evident that phosphorylation of the alpha (α) subunit of the translation initiation factor eIF2 at serine 51 (eIF2αS51P) is an important determinant of cell fate in response to stress. Induction of eIF2αS51P is mediated by a family of four kinases namely, HRI, PKR, PERK and GCN2, each of which responds to distinct forms of stress. Increased eIF2αS51P results in a global inhibition of protein synthesis but at the same time enhances the translation of select mRNAs encoding for proteins that control cell adaptation to stress. Short-term induction of eIF2αS51P has been associated with cell survival whereas long-term induction with cell death. Studies in mouse and human models of cancer have provided compelling evidence that eIF2αS51P plays an essential role in stress-induced tumorigenesis. Increased eIF2αS51P exhibits cell autonomous as well as immune regulatory effects, which can influence tumor growth and the efficacy of anti-tumor therapies. The findings suggest that eIF2αS51P may be of prognostic value and a suitable target for the design and implementation of effective anti-tumor therapies. This article is part of a Special Issue entitled: Translation and Cancer.
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Affiliation(s)
- Antonis E Koromilas
- Lady Davis Institute for Medical Research-McGill University, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada; Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec H2W 1S6, Canada.
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27
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Li H, Dusseault J, Larose L. Nck1 depletion induces activation of the PI3K/Akt pathway by attenuating PTP1B protein expression. Cell Commun Signal 2014; 12:71. [PMID: 25398386 PMCID: PMC4236421 DOI: 10.1186/s12964-014-0071-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 10/19/2014] [Indexed: 12/17/2022] Open
Abstract
Background Activation of the PI3K/Akt pathway mediates crucial cellular functions regulated by receptor tyrosine kinases, such as cell growth, proliferation, survival and metabolism. Previously, we reported that the whole-body knockout of the Src homology domain-containing adaptor protein Nck1 improves overall glucose homeostasis and insulin-induced activation of the PI3K/Akt pathway in liver of obese mice. The aim of the current study is to elucidate the mechanism by which Nck1 depletion regulates hepatic insulin signaling. Results Here, we demonstrate that Nck1 regulates the activation of the PI3K/Akt pathway in a protein tyrosine phosphatase 1B (PTP1B)-dependent mechanism. Indeed, depletion of Nck1 by siRNA in HepG2 cells enhances PI3K-dependent basal and growth factor-induced Akt activation. In accordance, primary hepatocytes isolated from Nck1−/− mice also display enhanced Akt activation in response to insulin. Activation of the PI3K/Akt pathway in Nck1-depleted HepG2 cells relies on higher levels of tyrosine-phosphorylated proteins and correlates with decreased PTP1B levels. Interestingly, Nck1 and PTP1B in cells are found in a common molecular complex and their interaction is dependent on the SH3 domains of Nck1. Finally, Nck1 depletion in HepG2 cells neither affects PTP1B gene transcription nor PTP1B protein stability, suggesting that Nck1 modulates PTP1B expression at the translational level. Conclusion Our study provides strong evidence supporting that the adaptor protein Nck1 interacts with PTP1B and also regulates PTP1B expression. In this manner, Nck1 plays a role in regulating the PI3K/Akt pathway.
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Affiliation(s)
- Hui Li
- Department of Medicine, Polypeptide Laboratory, McGill University and The Research Institute of McGill University Health Centre, Montreal, QC, Canada.
| | - Julie Dusseault
- Department of Medicine, Polypeptide Laboratory, McGill University and The Research Institute of McGill University Health Centre, Montreal, QC, Canada.
| | - Louise Larose
- Department of Medicine, Polypeptide Laboratory, McGill University and The Research Institute of McGill University Health Centre, Montreal, QC, Canada.
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Bakke J, Haj FG. Protein-tyrosine phosphatase 1B substrates and metabolic regulation. Semin Cell Dev Biol 2014; 37:58-65. [PMID: 25263014 DOI: 10.1016/j.semcdb.2014.09.020] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/15/2014] [Accepted: 09/21/2014] [Indexed: 01/19/2023]
Abstract
Metabolic homeostasis requires integration of complex signaling networks which, when deregulated, contribute to metabolic syndrome and related disorders. Protein-tyrosine phosphatase 1B (PTP1B) has emerged as a key regulator of signaling networks that are implicated in metabolic diseases such as obesity and type 2 diabetes. In this review, we examine mechanisms that regulate PTP1B-substrate interaction, enzymatic activity and experimental approaches to identify PTP1B substrates. We then highlight findings that implicate PTP1B in metabolic regulation. In particular, insulin and leptin signaling are discussed as well as recently identified PTP1B substrates that are involved in endoplasmic reticulum stress response, cell-cell communication, energy balance and vesicle trafficking. In summary, PTP1B exhibits exquisite substrate specificity and is an outstanding pharmaceutical target for obesity and type 2 diabetes.
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Affiliation(s)
- Jesse Bakke
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States
| | - Fawaz G Haj
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States; Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of California Davis, Sacramento, CA 95817, United States; Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, United States.
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Liu S, Xi Y, Bettaieb A, Matsuo K, Matsuo I, Kulkarni RN, Haj FG. Disruption of protein-tyrosine phosphatase 1B expression in the pancreas affects β-cell function. Endocrinology 2014; 155:3329-38. [PMID: 24956127 PMCID: PMC4138572 DOI: 10.1210/en.2013-2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and energy balance. However, the role of PTP1B in pancreatic endocrine function remains largely unknown. To investigate the metabolic role of pancreatic PTP1B, we generated mice with pancreas PTP1B deletion (panc-PTP1B KO). Mice were fed regular chow or a high-fat diet, and metabolic parameters, insulin secretion and glucose tolerance were determined. On regular chow, panc-PTP1B KO and control mice exhibited comparable glucose tolerance whereas aged panc-PTP1B KO exhibited mild glucose intolerance. Furthermore, high-fat feeding promoted earlier impairment of glucose tolerance and attenuated glucose-stimulated insulin secretion in panc-PTP1B KO mice. The secretory defect in glucose-stimulated insulin secretion was recapitulated in primary islets ex vivo, suggesting that the effects were likely cell-autonomous. At the molecular level, PTP1B deficiency in vivo enhanced basal and glucose-stimulated tyrosyl phosphorylation of EphA5 in islets. Consistently, PTP1B overexpression in the glucose-responsive MIN6 β-cell line attenuated EphA5 tyrosyl phosphorylation, and substrate trapping identified EphA5 as a PTP1B substrate. In summary, these studies identify a novel role for PTP1B in pancreatic endocrine function.
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Affiliation(s)
- Siming Liu
- Nutrition Department (S.L., Y.X., A.B., K.M., I.M., F.G.H.), University of California Davis, Davis, California 95616; Joslin Diabetes Center (R.N.K.), Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215; and Division of Endocrinology, Diabetes and Metabolism (F.G.H.), Department of Internal Medicine, and Comprehensive Cancer Center, University of California Davis, Sacramento, California 95817
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Nezvitsky L, Tremblay ML, Takano T, Papillon J, Cybulsky AV. Complement-mediated glomerular injury is reduced by inhibition of protein-tyrosine phosphatase 1B. Am J Physiol Renal Physiol 2014; 307:F634-47. [DOI: 10.1152/ajprenal.00191.2014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The unfolded protein response and endoplasmic reticulum-associated degradation (ERAD) contribute to injury in renal glomerular diseases, including those mediated by complement C5b-9. In the present study, we address the role of protein-tyrosine phosphatase 1B (PTP1B) in complement-mediated glomerular injury and ERAD. In glomerular epithelial cells (GECs)/podocytes and PTP1B-deficient mouse embryonic fibroblasts exposed to complement, inhibition/deletion of PTP1B reduced ERAD, as monitored by the ERAD reporter CD3δ. Overexpression of PTP1B produced an effect similar to PTP1B deficiency on ERAD in complement-treated GECs. Complement-mediated cytotoxicity was reduced after PTP1B overexpression and tended to be reduced after PTP1B inhibition. PTP1B enhanced the induction of certain ERAD components via the inositol-requiring-1α branch of the unfolded protein response. PTP1B knockout mice with anti-glomerular basement membrane glomerulonephritis had decreased proteinuria and showed less podocyte loss and endoplasmic reticulum dysfunction compared with wild-type littermates. These results imply that endogenous levels of PTP1B are tightly regulated and that both overexpression and inhibition can affect ERAD. The cytoprotective effects of PTP1B deletion in cultured cells and in anti-glomerular basement membrane nephritis suggest that PTP1B may potentially be a therapeutic target in complement-mediated diseases.
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Affiliation(s)
- Lisa Nezvitsky
- Department of Medicine and Biochemistry, McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Michel L. Tremblay
- Department of Medicine and Biochemistry, McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Tomoko Takano
- Department of Medicine and Biochemistry, McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Joan Papillon
- Department of Medicine and Biochemistry, McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Andrey V. Cybulsky
- Department of Medicine and Biochemistry, McGill University Health Centre, McGill University, Montreal, Quebec, Canada
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Choi HR, Kim WK, Park A, Jung H, Han BS, Lee SC, Bae KH. Protein tyrosine phosphatase profiling studies during brown adipogenic differentiation of mouse primary brown preadipocytes. BMB Rep 2014; 46:539-43. [PMID: 24152912 PMCID: PMC4133841 DOI: 10.5483/bmbrep.2013.46.11.058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 03/16/2013] [Accepted: 03/31/2013] [Indexed: 11/20/2022] Open
Abstract
There is a correlation between obesity and the amount of brown adipose tissue; however, the molecular mechanism of brown adipogenic differentiation has not been as extensively studied. In this study, we performed a protein tyrosine phosphatase (PTP) profiling analysis during the brown adipogenic differentiation of mouse primary brown preadipocytes. Several PTPs, including PTPRF, PTPRZ, and DUSP12 showing differential expression patterns were identified. In the case of DUSP12, the expression level is dramatically downregulated during brown adipogenesis. The ectopic expression of DUSP12 using a retroviral expression system induces the suppression of adipogenic differentiation, whereas a catalytic inactive DUSP12 mutant showed no effect on differentiation. These results suggest that DUSP12 is involved in brown adipogenic differentiation and may be used as a target protein for the treatment or prevention of obesity by the regulation of brown adipogenic differentiation.
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Affiliation(s)
- Hye-Ryung Choi
- Research Center for Integrated Cellulomics, KRIBB; Department of Functional Genomics, University of Science and Technology (UST), Daejeon 305-806, Korea
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Fernandez-Ruiz R, Vieira E, Garcia-Roves PM, Gomis R. Protein tyrosine phosphatase-1B modulates pancreatic β-cell mass. PLoS One 2014; 9:e90344. [PMID: 24587334 PMCID: PMC3938680 DOI: 10.1371/journal.pone.0090344] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 02/02/2014] [Indexed: 12/31/2022] Open
Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of the insulin signalling pathway. It has been demonstrated that PTP1B deletion protects against the development of obesity and Type 2 Diabetes, mainly through its action on peripheral tissues. However, little attention has been paid to the role of PTP1B in β-cells. Therefore, our aim was to study the role of PTP1B in pancreatic β-cells. Silencing of PTP1B expression in a pancreatic β-cell line (MIN6 cells) reveals the significance of this endoplasmic reticulum bound phosphatase in the regulation of cell proliferation and apoptosis. Furthermore, the ablation of PTP1B is able to regulate key proteins involved in the proliferation and/or apoptosis pathways, such as STAT3, AKT, ERK1/2 and p53 in isolated islets from PTP1B knockout (PTP1B −/−) mice. Morphometric analysis of pancreatic islets from PTP1B −/− mice showed a higher β-cell area, concomitantly with higher β-cell proliferation and a lower β-cell apoptosis when compared to islets from their respective wild type (WT) littermates. At a functional level, isolated islets from 8 weeks old PTP1B −/− mice exhibit enhanced glucose-stimulated insulin secretion. Moreover, PTP1B −/− mice were able to partially reverse streptozotocin-induced β-cell loss. Together, our data highlight for the first time the involvement of PTP1B in β-cell physiology, reinforcing the potential of this phosphatase as a therapeutical target for the treatment of β-cell failure, a central aspect in the pathogenesis of Type 2 Diabetes.
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MESH Headings
- Animals
- Apoptosis
- Cell Count
- Cell Line
- Cell Proliferation
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/enzymology
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/pathology
- Endoplasmic Reticulum/chemistry
- Endoplasmic Reticulum/enzymology
- Gene Expression Regulation
- Glucose/metabolism
- Glucose/pharmacology
- Insulin/metabolism
- Insulin Secretion
- Insulin-Secreting Cells/drug effects
- Insulin-Secreting Cells/enzymology
- Insulin-Secreting Cells/pathology
- Male
- Mice
- Mice, Knockout
- Mitogen-Activated Protein Kinase 1/genetics
- Mitogen-Activated Protein Kinase 1/metabolism
- Protein Tyrosine Phosphatase, Non-Receptor Type 1/antagonists & inhibitors
- Protein Tyrosine Phosphatase, Non-Receptor Type 1/genetics
- Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- STAT3 Transcription Factor/genetics
- STAT3 Transcription Factor/metabolism
- Signal Transduction
- Streptozocin
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/metabolism
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Affiliation(s)
- Rebeca Fernandez-Ruiz
- Diabetes and Obesity Research Laboratory, Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Elaine Vieira
- Diabetes and Obesity Research Laboratory, Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Pablo M. Garcia-Roves
- Diabetes and Obesity Research Laboratory, Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Ramon Gomis
- Diabetes and Obesity Research Laboratory, Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
- Universitat de Barcelona, Barcelona, Spain
- Hospital Clinic de Barcelona, Barcelona, Spain
- * E-mail:
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33
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Koromilas AE, Mounir Z. Control of oncogenesis by eIF2α phosphorylation: implications in PTEN and PI3K-Akt signaling and tumor treatment. Future Oncol 2014; 9:1005-15. [PMID: 23837763 DOI: 10.2217/fon.13.49] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
mRNA translation plays an important role in tumor development and represents a valid target of pharmaceutical intervention in cancer. A key step in mRNA translation involves the regulation of initiation by the eukaryotic initiation factor eIF2. Eukaryotic cells respond to various forms of stress by inducing the phosphorylation of the α-subunit of eIF2 at S51, a modification that leads to protein synthesis inhibition. Phosphorylated eIF2α can act either as a promoter of cell survival or an inducer of cell death in response to distinct stimuli. Increased eIF2α phosphorylation has a cytoprotective function in response to genetic or pharmacological inhibition of the PI3K-Akt pathway but also exhibits a proapoptotic function downstream of the PTEN tumor suppressor, independent of PI3K-Akt signaling inhibition. The functional interplay between the PI3K-Akt and eIF2α phosphorylation pathways may have important implications in the design of anti-tumor therapies that depend on the cell fate decisions of phosphorylated eIF2α.
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34
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Yamani L, Latreille M, Larose L. Interaction of Nck1 and PERK phosphorylated at Y⁵⁶¹ negatively modulates PERK activity and PERK regulation of pancreatic β-cell proinsulin content. Mol Biol Cell 2013; 25:702-11. [PMID: 24371088 PMCID: PMC3937095 DOI: 10.1091/mbc.e13-09-0511] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
PERK is phosphorylated at Y561 in the juxtamembrane domain, and the adaptor protein Nck1, by directly interacting with phospho-Y561 PERK, negatively regulates PERK activity. Strong evidence is given supporting the biological relevance of Nck1 regulation of PERK function in modulating pancreatic β-cell proinsulin content. PERK, the PKR-like endoplasmic reticulum (ER) kinase, is an ER transmembrane serine/threonine protein kinase activated during ER stress. In this study, we provide evidence that the Src-homology domain–containing adaptor Nck1 negatively regulates PERK. We show that Nck directly binds to phosphorylated Y561 in the PERK juxtamembrane domain through its SH2 domain. We demonstrate that mutation of Y561 to a nonphosphorylatable residue (Y561F) promotes PERK activity, suggesting that PERK phosphorylation at Y561 (pY561PERK) negatively regulates PERK. In agreement, we show that pY561PERK delays PERK activation and signaling during ER stress. Compatible with a role for PERK in pancreatic β-cells, we provide strong evidence that Nck1 contributes to PERK regulation of pancreatic β-cell proteostasis. In fact, we demonstrated that down-regulation of Nck1 in mouse insulinoma MIN6 cells results in faster dephosphorylation of pY561PERK, which correlates with enhanced PERK activation, increased insulin biosynthesis, and PERK-dependent increase in proinsulin content. Furthermore, we report that pancreatic islets in whole-body Nck1-knockout mice contain more insulin than control littermates. Together our data strongly suggest that Nck1 negatively regulates PERK by interacting with PERK and protecting PERK from being dephosphorylated at its inhibitory site pY561 and in this way affects pancreatic β-cell proinsulin biogenesis.
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Affiliation(s)
- Lama Yamani
- Polypeptide Laboratory, Department of Medicine, and Health Centre Research Institute, McGill University, Montreal, QC H3A 2B2, Canada
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35
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Taheripak G, Bakhtiyari S, Rajabibazl M, Pasalar P, Meshkani R. Protein tyrosine phosphatase 1B inhibition ameliorates palmitate-induced mitochondrial dysfunction and apoptosis in skeletal muscle cells. Free Radic Biol Med 2013; 65:1435-1446. [PMID: 24120971 DOI: 10.1016/j.freeradbiomed.2013.09.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 08/16/2013] [Accepted: 09/23/2013] [Indexed: 01/09/2023]
Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of the insulin signaling pathway and is considered a promising therapeutic target in the treatment of diabetes. However, the role of PTP1B in palmitate-induced mitochondrial dysfunction and apoptosis in skeletal muscle cells has not been studied. Here we investigate the effects of PTP1B modulation on mitochondrial function and apoptosis and elucidate the underlying mechanisms in skeletal muscle cells. PTP1B inhibition significantly reduced palmitate-induced mitochondrial dysfunction and apoptosis in C2C12 cells, as these cells had increased expression levels of PGC-1α, Tfam, and NRF-1; enhanced ATP level and cellular viability; decreased TUNEL-positive cells; and decreased caspase-3 and -9 activity. Alternatively, overexpression of PTP1B resulted in mitochondrial dysfunction and apoptosis in these cells. PTP1B silencing improved mitochondrial dysfunction by an increase in the expression of SIRT1 and a reduction in the phosphorylation of p65 NF-κB. The protection from palmitate-induced apoptosis by PTP1B inhibition was also accompanied by a decrease in protein level of serine palmitoyl transferase, thus resulting in lower ceramide content in muscle cells. Exogenous addition of C2-ceramide to PTP1B-knockdown cells led to a reduced generation of reactive oxygen species (ROS), whereas PTP1B overexpression demonstrated an elevated ROS production in myotubes. In addition, PTP1B inhibition was accompanied by decreased JNK phosphorylation and increased insulin-stimulated Akt (Ser473) phosphorylation, whereas overexpression of PTP1B had the opposite effect. The overexpression of PTP1B also induced the nuclear localization of FOXO-1, but in contrast, suppression of PTP1B reduced palmitate-induced nuclear localization of FOXO-1. In summary, our results indicate that PTP1B modulation results in (1) alterations in mitochondrial function by changes in the activity of SIRT1/NF-κB/PGC-1α pathways and (2) changes in apoptosis that result from either a direct effect of PTP1B on the insulin signaling pathway or an indirect influence on ceramide content, ROS generation, JNK activation, and FOXO-1 nuclear translocation.
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Affiliation(s)
- Gholamreza Taheripak
- Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran 1416753955, Iran
| | - Salar Bakhtiyari
- Department of Clinical Biochemistry, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran
| | - Masoumeh Rajabibazl
- Department of Clinical Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parvin Pasalar
- Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran 1416753955, Iran
| | - Reza Meshkani
- Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran 1416753955, Iran.
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36
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Nguyen PH, Yang JL, Uddin MN, Park SL, Lim SI, Jung DW, Williams DR, Oh WK. Protein tyrosine phosphatase 1B (PTP1B) inhibitors from Morinda citrifolia (Noni) and their insulin mimetic activity. JOURNAL OF NATURAL PRODUCTS 2013; 76:2080-2087. [PMID: 24224843 DOI: 10.1021/np400533h] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
As part of our ongoing search for new antidiabetic agents from medicinal plants, we found that a methanol extract of Morinda citrifolia showed potential stimulatory effects on glucose uptake in 3T3-L1 adipocyte cells. Bioassay-guided fractionation of this active extract yielded two new lignans (1 and 2) and three new neolignans (9, 10, and 14), as well as 10 known compounds (3-8, 11-13, and 15). The absolute configurations of compounds 9, 10, and 14 were determined by ECD spectra analysis. Compounds 3, 6, 7, and 15 showed inhibitory effects on PTP1B enzyme with IC50 values of 21.86 ± 0.48, 15.01 ± 0.20, 16.82 ± 0.42, and 4.12 ± 0.09 μM, respectively. Furthermore, compounds 3, 6, 7, and 15 showed strong stimulatory effects on 2-NBDG uptake in 3T3-L1 adipocyte cells. This study indicated the potential of compounds 3, 6, 7, and 15 as lead molecules for antidiabetic agents.
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Affiliation(s)
- Phi-Hung Nguyen
- College of Pharmacy, Chosun University , Gwangju 501-759, Republic of Korea
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37
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Zhou W, Jeyaraman K, Yusoff P, Shenolikar S. Phosphorylation at tyrosine 262 promotes GADD34 protein turnover. J Biol Chem 2013; 288:33146-55. [PMID: 24092754 DOI: 10.1074/jbc.m113.504407] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In mammalian cells, metabolic and environmental stress increases the phosphorylation of the eukaryotic translational initiation factor, eIF2α, and attenuates global protein synthesis. Subsequent transcriptional activation of GADD34 assembles an eIF2α phosphatase that feeds back to restore mRNA translation. Active proteasomal degradation of GADD34 protein then reestablishes the sensitivity of cells to subsequent bouts of stress. Mass spectrometry established GADD34 phosphorylation on multiple serines, threonines, and tyrosines. Phosphorylation at tyrosine 262 enhanced the rate of the GADD34 protein turnover. Substrate-trapping studies identified TC-PTP (PTPN2) as a potential GADD34 phosphatase, recognizing phosphotyrosine 262. Reduced GADD34 protein levels in TC-PTP-null MEFs following ER stress emphasized the importance of TC-PTP in determining the cellular levels of GADD34 protein. The susceptibility of TC-PTP-null MEFs to ER stress-induced apoptosis was significantly ameliorated by ectopic expression of GADD34. The data suggested that GADD34 phosphorylation on tyrosine 262 modulates endoplasmic reticulum stress signaling and cell fate.
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Affiliation(s)
- Wei Zhou
- From the Signature Research Programs in Cardiovascular and Metabolic Disorders and
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38
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Bakke J, Bettaieb A, Nagata N, Matsuo K, Haj FG. Regulation of the SNARE-interacting protein Munc18c tyrosine phosphorylation in adipocytes by protein-tyrosine phosphatase 1B. Cell Commun Signal 2013; 11:57. [PMID: 23937695 PMCID: PMC3751566 DOI: 10.1186/1478-811x-11-57] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 08/06/2013] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of insulin signaling and adiposity and is a drug target for the treatment of obesity and diabetes. The molecular mechanisms underlying PTP1B metabolic actions require additional investigation. RESULTS Herein, we identify Munc18c as a novel PTP1B substrate in adipocytes and in vivo. We demonstrate nutritional regulation of Munc18c in adipose tissue revealing decreased expression upon high fat feeding. In addition, PTP1B deficiency leads to elevated Munc18c tyrosine phosphorylation and dissociation from syntaxin4. At the molecular level, we identify Munc18c Tyr218/219 and Tyr521 as key residues that mediate Munc18c interaction with PTP1B. Further, we uncover an essential role of Munc18c total tyrosine phosphorylation in general, and Tyr218/219 and Tyr521 in particular, in regulating its interactions and glucose uptake in adipocytes. CONCLUSION In conclusion, our findings identify PTP1B as the first known tyrosine phosphatase for Munc18c and a regulator of its phosphorylation and function in adipocytes.
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Affiliation(s)
- Jesse Bakke
- Nutrition Department, University of California Davis, One Shields Ave, 3135 Meyer Hall, Davis, CA 95616, USA
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39
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Feldhammer M, Uetani N, Miranda-Saavedra D, Tremblay ML. PTP1B: a simple enzyme for a complex world. Crit Rev Biochem Mol Biol 2013; 48:430-45. [PMID: 23879520 DOI: 10.3109/10409238.2013.819830] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Our understanding of the fundamental regulatory roles that tyrosine phosphatases play within cells has advanced significantly in the last two decades. Out-dated ideas that tyrosine phosphatases acts solely as the "off" switch counterbalancing the action of tyrosine kinases has proved to be flawed. PTP1B is the most characterized of all the tyrosine phosphatases and it acts as a critical negative and positive regulator of numerous signaling cascades. PTP1B's direct regulation of the insulin and the leptin receptors makes it an ideal therapeutic target for type II diabetes and obesity. Moreover, the last decade has also seen several reports establishing PTP1B as key player in cancer serving as both tumor suppressor and tumor promoter depending on the cellular context. Despite many key advances in these fields one largely ignored area is what role PTP1B may play in the modulation of immune signaling. The important recognition that PTP1B is a major negative regulator of Janus kinase - signal transducer and activator of transcription (JAK-STAT) signaling throughout evolution places it as a key link between metabolic diseases and inflammation, as well as a unique regulator between immune response and cancer. This review looks at the emergence of PTP1B through evolution, and then explore at the cell and systemic levels how it is controlled physiologically. The second half of the review will focus on the role(s) PTP1B can play in disease and in particular its involvement in metabolic syndromes and cancer. Finally we will briefly examine several novel directions in the development of PTP1B pharmacological inhibitors.
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40
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Pan D, Zhang D, Wu J, Chen C, Xu Z, Yang H, Zhou P. Antidiabetic, antihyperlipidemic and antioxidant activities of a novel proteoglycan from ganoderma lucidum fruiting bodies on db/db mice and the possible mechanism. PLoS One 2013; 8:e68332. [PMID: 23874589 PMCID: PMC3708940 DOI: 10.1371/journal.pone.0068332] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 05/28/2013] [Indexed: 11/25/2022] Open
Abstract
Previously, we screened a proteoglycan for anti-hyperglycemic, named FYGL, from Ganoderma Lucidum. For further research of the antidiabetic mechanisms of FYGL in vivo, the glucose homeostasis, activities of insulin-sensitive enzymes, glucose transporter expression and pancreatic function were analyzed using db/db mice as diabetic models in the present work. FYGL not only lead to a reduction in glycated hemoglobin level, but also an increase in insulin and C-peptide level, whereas a decrease in glucagons level and showed a potential for the remediation of pancreatic islets. FYGL also increased the glucokinase activities, and simultaneously lowered the phosphoenol pyruvate carboxykinase activities, accompanied by a reduction in the expression of hepatic glucose transporter protein 2, while the expression of adipose and skeletal glucose transporter protein 4 was increased. Moreover, the antioxidant enzyme activities were also increased by FYGL treatment. Thus, FYGL was an effective antidiabetic agent by enhancing insulin secretion and decreasing hepatic glucose output along with increase of adipose and skeletal muscle glucose disposal in the late stage of diabetes. Furthermore, FYGL is beneficial against oxidative stress, thereby being helpful in preventing the diabetic complications.
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Affiliation(s)
- Deng Pan
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, P. R. China
| | - Dang Zhang
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, P. R. China
| | - Jiasheng Wu
- Pharmacy College, Shanghai University of Traditional Chinese Medicine, Shanghai, P. R. China
| | - Congheng Chen
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, P. R. China
| | - Zhixue Xu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, P. R. China
| | - Hongjie Yang
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, P. R. China
- * E-mail: (PZ); (HY)
| | - Ping Zhou
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, P. R. China
- * E-mail: (PZ); (HY)
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41
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Bettaieb A, Bakke J, Nagata N, Matsuo K, Xi Y, Liu S, AbouBechara D, Melhem R, Stanhope K, Cummings B, Graham J, Bremer A, Zhang S, Lyssiotis CA, Zhang ZY, Cantley LC, Havel PJ, Haj FG. Protein tyrosine phosphatase 1B regulates pyruvate kinase M2 tyrosine phosphorylation. J Biol Chem 2013; 288:17360-71. [PMID: 23640882 PMCID: PMC3682537 DOI: 10.1074/jbc.m112.441469] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 04/24/2013] [Indexed: 11/06/2022] Open
Abstract
Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and adiposity and is a drug target for the treatment of obesity and diabetes. Here we identify pyruvate kinase M2 (PKM2) as a novel PTP1B substrate in adipocytes. PTP1B deficiency leads to increased PKM2 total tyrosine and Tyr(105) phosphorylation in cultured adipocytes and in vivo. Substrate trapping and mutagenesis studies identify PKM2 Tyr-105 and Tyr-148 as key sites that mediate PTP1B-PKM2 interaction. In addition, in vitro analyses illustrate a direct effect of Tyr-105 phosphorylation on PKM2 activity in adipocytes. Importantly, PTP1B pharmacological inhibition increased PKM2 Tyr-105 phosphorylation and decreased PKM2 activity. Moreover, PKM2 Tyr-105 phosphorylation is regulated nutritionally, decreasing in adipose tissue depots after high-fat feeding. Further, decreased PKM2 Tyr-105 phosphorylation correlates with the development of glucose intolerance and insulin resistance in rodents, non-human primates, and humans. Together, these findings identify PKM2 as a novel substrate of PTP1B and provide new insights into the regulation of adipose PKM2 activity.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Kimber Stanhope
- From the Nutrition Department and
- Department of Molecular Biosciences, University of California Davis, Davis, California 95616
| | - Bethany Cummings
- From the Nutrition Department and
- Department of Molecular Biosciences, University of California Davis, Davis, California 95616
| | - James Graham
- From the Nutrition Department and
- Department of Molecular Biosciences, University of California Davis, Davis, California 95616
| | - Andrew Bremer
- the Department of Pediatrics, Vanderbilt University, Nashville, Tennessee 37232
| | - Sheng Zhang
- the Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202
| | - Costas A. Lyssiotis
- the Beth Israel Deaconess Medical Center, Department of Medicine, and
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Zhong-Yin Zhang
- the Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202
| | - Lewis C. Cantley
- the Beth Israel Deaconess Medical Center, Department of Medicine, and
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Peter J. Havel
- From the Nutrition Department and
- Department of Molecular Biosciences, University of California Davis, Davis, California 95616
| | - Fawaz G. Haj
- From the Nutrition Department and
- the Department of Internal Medicine and
- Comprehensive Cancer Center, University of California Davis, Sacramento, California 95817
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